Why is my acid stain not taking?

The question to be answered is why does and acid stain not take and how can I resolve this issue.

The question came in as:

Question…I’m in the middle of acid staining my concrete basement floor. When I began the neutralizing/washing process, the acid stain is wiping away…even as I barely mop it. I don’t know what to do at this point. I asked a lot of questions prior to beginning the project and was diligent about following them.

Here is my best response:

Acid stain is reactive and needs to react and burn into the concrete surface. If the concrete was sealed with a sealer or was power trowled too tight this may impede the stain from penetrating.

Another reason the stain is washing away may be because of the age of the concrete and the amount of free lime in it. Acid stain reacts and attaches to free lime in concrete and a lack of, or absence of free lime may cause the stain to easily wash away.

Acid stain should be tested on a small area and then cleaned and sealed to ensure its success on the main area of flooring. If an acid stain is not taking to a concrete slab you may consider using a dye instead. Concrete dyes do not rely on a chemical reaction. It is however advantageous to have a profiled surface for them and the subsequent sealer to adhere to.

Concrete before acid washing

Concrete after acid washing

If you are unsure about the application of a product or its effectiveness the manufacturer should be able to help and find a solution.